If video is your 'Net medium, then take a look at VidMeter - it's sort of like a meta-search engine to determine what's hot in the realm of video content based on the number of views, and comments.
Tracking the top videos from Break.com, Daily Motion, Google, iFilm, Metacafe, Myspace, Revver, vSocial, Yahoo, and Youtube once per hour, Vidmeter editors also "merge" similar videos on multiple websites. This allows Vidmeter to count the views of a video on all websites as a single video, giving a more accurate ranking of a video's popularity and not just a URL's popularity. Vidmeter then automatically ranks videos for the day by counting the difference between that day's view total and the previous day's view total. The most viewed videos are the most popular and ranked highest. Finally, the latest view and comment counts are set as the "all time" counts for the videos and they are ranked accordingly.
VidMeter aims to be the "Billboard 100" of online videos and show industry watchers what's hot, how their videos are performing, and show advertisers where to buy and how their ads are doing, as well as show avid watchers the latest videos. The only downside for me was that the search box didn't really seem to work at all - if it does it needs some explanation on how to get something, anything to appear.